Hang out around Embarcadero Station during evening rush or 4th & King sometime. It's a real mess. I've seen 4 busses running back to back, and some mornings I'll see 5 or more trains backed up. Not to mention the entire system already runs at a snail's pace. I generally bike, and I will usually get there in about 1/2 the time. Compare to Chicago where there's no way I could outrun a CTA bus, let alone the trains.